If mastodon had a security hole they could all be owned at the same time. Fediverse servers on different software would be unaffected unless the hole is in a library used by both.
To be fair, the article is just part of a challenge to write 100 blog posts in 100 days. Nothing wrong with writing whatever you want, although the title of the post is still terrible. The question is, why did anyone think this article was worth submitting to HN?
Yes I'm aware. An inside job against mastodon would be harder. A few people may be able to deliberately insert malicious code but that goes for any open source project.
To be fair, the article is just part of a challenge to write 100 blog posts in 100 days. Nothing wrong with writing whatever you want, although the title of the post is still terrible. The question is, why did anyone think this article was worth submitting to HN?